Ore-concentrating apparatus.



J. M. CALLOW.

ORE GONGENTRATING APPARATUS.

APPLICATION IILED D150. 13, 1913.

Patented July 21, 1914.

" TED STATES PAT OFFICE.

EDEN 1E. CAI-LOW, 0F SALT LAKE CITY, UTAH, ASSIGNDB TO IETALS RECOVERY GOHPAHY, 0F AUGUSTA, MAINE, A CORPORATION OF MAINE.

OBE-CONCENTRATING APPARATUS.

Specification of Letters Eatent.

Patented July 21, 1914.

- ren or rocky constituents thereof, and the invention consists of the parts and the constructions, arrangements and combinations of parts which I will hereinafter fully describe and claim.

In the accompanying drawings forming partof this specification, and in which similar reference characters indicate like parts in the several views:Figure 1 illustrates a side elevation of an apparatus for the concentration of ores embodying my invention. Fig. 2 is an enlarged vertical sectional view of one of the concentrating tanks or vessels supplied with thepresent improvements. Fi 3 is a cross-sectional view on the line -X of Fig. 2, showing the arrangement of the vertically-disposed bafiies.

In my former application filed October 6, 1913, Serial Number 793,695, I have disclosed and claimed an ore concentrating apparatus similar to the one shown in the present instance, without the sweep herein disclosed and claimed and which apparatus relates to an art which is distinguished from the usual amalgamation processes in which the ore forms an amalgam, and being identified more particularly with what is now known as flotation processes, wherein a certain percentage of oil, or of two dissimilar oils, or an oil and an acid, or an oil or an alkali, is mixed with finely ground ore pulp, and the mixture then subjected to a violent agitation by means of mechanical propellers. The 'result is that large quantities of air are beaten into and entrained by the pulp, which action produces a froth composed of bubbles of air and oil, to which the mineral particles are attached. This froth has the appearance of an aggregation or a mas of fine-and small soap bubbles,

which, .when collected and the froth discharged or broken down, by natural settlement, or by the additionoi cold water, or other means, displaces the mineral particles that have been caught.

In my aforesaid former application, I disclose a means for impregnating the pulp with a large volume of air, which seems to be necesary, or desirable, for aerating the pulp, and I provide a means for adding to the pulp containing the proper percentage of oil, or other reagent, compressed air which is introduced into the pulp from beneath through some porous body and in innumerable fine streams orjets, this being for the purpose of both aerating and agitating the pulp, the compressed air thus becoming the medium of (1) aerating or charging the pulp with the desired volume of air, and (2), it likewise induces and maintains that agitation of the pulp which heretofore was obtained by mechanical propellers and stirrers. The advantages oi the -foregoing steps are fully set forth in the prior application referred to.

- In the drawings I have shown for illustrative purposes a type of apparatus which closely follows the one disclosed in the former application and wherein A is a feed tank of any suitable character supported upon a. framework, which will elevate the tank a suflicient height to insure a satisfactory gravity feed of the pulp to the balance of the apparatus, it being understood that this tank is adapted to receive ore-pulp together with its carrying water and which pulp may be fed to the tank through a pipe line, A, as indicated in Fig. 1.

Disposed adjacent and above the feed tank is a vessel, C, adapted to contain one of the reagents, which I will call oil. D is a vessel adapted to contain another reagent, which I will call an acid. said vemels, C and D, having suitable cocks or valves. by which the percentage of reagent, say oil and acid, admitted with the ore-pulp and water may be regulated, as desired. The oil, the acid and the pulp mix in the feed tank, A, and are conveyed therefrom by a pipe, E, to the first of a series of tanks or receptacles in which the pulp is agitated and aerated. I have shown four of these tanks or receptacles, F, F, F and F, for

illustrative purposes, but it will be understood that the number of tanks used may be increased or diminished from what I have shown, without in any manner departing from the spirit of my invention.

The tanks or receptacles are preferably constructed alike and each consists of an outer casing-of suitable form, dimensions and construction, and an interior casing, K, of smaller size and separated from the walls of the outer vessel to form a circumscribing space, M, the purpose of which will hereinafter appear, said inner casing having, preferably,a flaring or funnel-shaped upper end.

In the upper part of the tank or receptacle, F, is suitably secured an inverted cone, S, the top or smaller end of which is :disposed below the top of the tank, said cone having its lower part connecting with the inner wall of the tank so as to form a gutter, S, in the upper portion of the tank between the cone and the inner wall of said tank. This gutter or launder, S, terminates in a spout, G, Fig. 1, at one side, and the spouts of the several tanks or receptacles, F, F and F which as before stated are similar in construction and arrangement, connect with a side launder or trough, H, which conveys the contents of the several gutters or launders, S, into an appropriate feed box,-I, from which box the contents are delivered by a pipe or down-take, J, into the final tank or receptacle, F, which I will hereinafter designate as a 5 cleaner, while the first three of the tanks, F, F and F I designate as roughers As before stated, the tanks have substantially the same design and construction, and the frothy concentrates made on the first three of the tanks are conducted by the side launder or trough. H, into the feed box, I, and then are conducted into the cleaner, F, through the pipe, J.

In the lower portion of the inner casing. K, of each tank or receptacle and elevated a suitable distance above the bottom thereof, is a porous medium, L, which is supported upon suitable brackets, or other rests, L. By elevating this porous medium above the bottom of the tank or receptacle, I am permitted to form between the bottom of said medium and the bottom of the tank, a chamber, P, which is 'cutofi' from communication with the upper portion of the tank, and with the pulp contents thereof, except through the pores of the medium, L, and which medium is centrally .pierced to admit the upturned end of the pipe, E, which conducts the pulp from the feed-tank into the ulp chamber of the tank, F. Thus the eed coming throu h the pi e,'E, is prevented from entering t e space helowthe porous medium, but is allowed to discharge itself throu h the upturned end of the 1 e, and direct y into the main chamber of t e vessel above said porous floor, or medium, L,

- material throug referred to. In practice, the pul is allowed to run into the tank or receptac e, until the latter is partly filled, the level of the water being variable according to the condition of the ore and the work to be accomplished.

As before stated, a space, M, is formed between the inner and outer casings of each tank, and this space forms a gutter or channel which connects with a discharge pipe, N, having a valve, 0, which controls the height of the water in the vessel by restricting the discharge. In other words, by the regulation of the "alve, O, in relation to the amount of feed, any level of pulp in the. vessel, F, can be maintained. The pipe, N, from tank or receptacle, F, leads into the second tank, F and through the porous medium, L, therein and the discharge from this second tank likewise leads into the third tank, and so on, until in the final tank or rougher, F the discharge will be through the pipe, W, said dischargebeing discarded and allowed to go to waste. 1

Compressed air is desi ed to be introduced into the chamber ormed below the porous medium, L, in each of the tanks or re-. ceptacles, including the cleaner, F and to this end, I admit the compressed air through a pipe, Q, from which a valve-controlled branch, Q, leads through the bottom of the tank and into the space, P, between the same and the under part of the porous medium, L. To prevent the air from impinging directly upon the porous medium immcdlately above the inlet end of the pipe, Q, I place over the discharge end of the pipe a shield or deflector, R. The pipe, Q, may be otherwise disposed, but in any event its function is to admit into the'chamber between the bottom of the porous medium and the bottom of the tank proper, a volume of compressed air.

The porous medium may be of any suitable construction and material; porousbrick, or a layer of fine sand between two restraining layers of screen cloth, or layers of fibrous material laid one above the other, such for instance as cocoa mattin or certain kinds of porous wood, such as asswood may be used, or in fact any porous material through which air can be forced in more or less irregular jets of infinite number and fineness. The character of the porous material employed is, therefore, unimportant, except that it shall have the property of ermitting the air introduced into the cham er, P, to be discharged through the pores of the out the entire surface thereof, and into the body of pulp in the chamber above, with the result that imme- 1 diately upon the introduction of the air, a violent agitation or ebullition takes place, and froth is observed to rise and form on the surface of the ulp contents, which greatly increases in v0 ume and density as the ac- 1 tion proceeds. As the froth accumulates above the surface of the. pulp within the vessel, h", it overflows the rim of the inside top cone, S, and continues to do so as long as the tank or vessel is supplied with the necessary ingredients of pulp, oil, acid and compressed air, and the overflowing froth is received into the gutter or annular launder, S, and finally is delivered into the feedoox. I, through the sidelaunder or trougl1,H. During this agitation of the pulp and the formation of the froth, the tailings settle into the annular space, M, formed between the tank and the inner casing. K; thereof, and the discharge of these tailings takes place through the discharge pipe, N. and through which pipe, the particles which are too heavy to float in the first tank and which have settled into the annular space. M, thereof. are delivered into the succeeding tank, F this action occurring in all of the tanks. and the waste material being delivered from the final or roughing tank. b through the discharge pipe, \V. before mentioned. In other words, the discharge from the first tank, F. makes feed for the succeeding tank, F and the discharge from the latter in turn makes feed for the next tank,

F. Each of these tanks in turn makes a frothy concentrate in the manner before described, and the froth of the several tanks is in turn led to the feed-box, I, from which latter it is discharged into the cleaner tank, F where a similar action occurs, and the rough or crude concentrates made on the first series are cleaned, or further refined by a similar action in the tank, F, the concentrates bein discharged therefrom through a side launder, U, and the tailings being delivered from the bottom of the tank. F, by means of a siphon-pipe, or otherwise.

It is customary to conduct the discharge from the cleaner tank, F, back to the original feed so that it may be again and again acted upon, and to this end, I have shown in Fig. l, the use of a pump, 10, for conducting the discharge from the cleaner tank back to the feed tank, A, through the medium of a suitable pipe, 8.

The close observation of experiments made with apparatus of this type has indicated some trouble with coarse sands accu mulating in the bottom of the tank and which tended to blanket the porous mediiun, L. and to some extent at least render this medium ineffective for the best results. So long as the pulp was infinitely fine and slimy. the air pressure was ample and the velocities maintained in the tank were sufiicientto discharge everything over the interior casing. K. and into the annular discharge gutter, but when treating comparatively coarse and sandy material the air pressure and velocities were found to be too low to raise these coarse sands over into the gutter so that they might be discharged; accordingly they would gradually accumulate to such an extent as to form a layer or blanket of sand above the porous medium and so prevent the free passage therethrough of the air. The air instead of being d1stributed over the entire surface of the pulp, would all come up through some small area which might represent a path of least resistance. and so, of course, destroy to some extent the action of the air. To meet this objection I found it desirable to maintain the sands in suspension, or in a condition of agitation and accordingly in the present in- -.-.tance. as shown in Fig. 2. I have jonrnaled in the central portion of the tank a vertical shaft, 10, the lower end of which carries suitable sweep-arms, or agitators, 11. which are disposed slightly above the upper surface of the porous medium. L. said shaft being suitably journaled in the framework of the machine, as indicated in Fig. 1, and carrying at its upper end a beveled gear, 12, which is in mesh with a similar gear, 13, on a horizontal shaft, 1%, to which power is applied through a suitable pulley, 15, or other medium, it being understood that each of the tanks, F, F F and F is provided with the vertical shaft, sweep-arms and gearing before noted. 4

It might be stated at this time that, as a matter of fact, the function of the sweeparms is not the same as that derived from the propellers or paddles sometimes employed in this art and which usually run at a high speed and are .for the specific purposeof agitating and beating into the pulp large quantities of air. In my apparatus, the sweep-arms or stirrers are solely and specifically for the purpose of keeping the coarse sands above referred to. in suspension and preventing their settling on and blanketing the porous medium and thus clogging the pores of the latter so as to prevent the free discharge of the air into the solution. This point will be'bettcr appreciated when attention is directed to the fact that the propellers which are sometimes used for beating into the pulp the necessary large quantities of air. are required to be run at a high speed. say a speed sutlicient to give a peripheral velocity at the tip of the blades of from 15 to 18 hundred feet per minute, whereas, in my invention where sweep-arms are used in proximity to the surface of the porous brick for the purpose of keeping the sands in suspension and preventing the blanketing of the outlets for the air, it is only necessary to have a peripheral velocity to the top surface of the porous medium for the purpose of keeping the coarse sands from depositing thereon and blanketing the outlets of the pores of said medium; and also a material difference between these sweep-arms and the high-speed propellers of the prior art which are designed solely for the purpose of beatin large quantities of air into the pulp, 'an which accordingly, do not co-act in any manner, nor are they used in connection with an underlying porous medium through which the air is admitted into the pulp, in numerous fine streams distributed substantially throughout the surface of the pulp. It will also be observed that in the present instance, I have disposed above the interior vessel, K, suitable baflles, 16, which baflles are shown as vertically disposed and as consisting of blades of substantial width having flanges by which they are secured to the inside of the tank, said blades projecting substantially radially into the tank and overhanging the inner vessel, K, and being for the purpose of preventing the entire mass of pulp circulating, said baflles being therefore, of a different construction and differently arranged and designed for a purpose different from that ascribed to the baflles of my? former atpplication.

rom the oregoing, it will be understood that I employ no mechanical propellers for producing the necessary agitation and beating into the froth of large volumes of air, but that I depend upon the compressed air admitted through a porous body which has the function of splitting up the air into innumerable fine streams and distributing these fine streams over and into substantially the entire surface of the pulp, whereby immediately upon the introduction of the air, a more or less violent agitation or ebullition takes place and a froth begins to generate and to finally rise and-form on the surface of the pulp, from which it is discharged in the manner described in my former application; that to maintain the surface of the porous medium substantially clean when using pulp charged with heavy sands, and to prevent closing of the pores of said medium and thus shuttin off the supply of air to the pulp, I emp oy arms which operate with a sweeping motion in proximity to the upper surface of the medium and which maintain the coarse sands in suspension and prevent their settling; and that I provide means for battling or preventing the entire mass being given a circular motion because of the action of the sweep-arms, and which arms rotate at a relatively slow speed and. at a speed which is not sufficient to beat into the ulp any considerable volume of air. In act they are notrequired for this purpose since I use compressed air admitted through "the porous medium for the purpose of charging the pulp and inducing the frothy action before referred to. V

Having thus described my invention what Iclaim as new and desire to secure by Letters Patent is 1. In ore concentrating apparatus having a solution-containing tank and a porous body therein through which fine streams of air under pressure are admitted into the solution from below, a means operating in proximity to the uppersurface ofsaid body, for maintaining the heavierconstituents of the solution in sus ension to thereby prevent the blanketing o porous body.

2. In ore concentrating apparatu a solution-containing tank, and a porous body therein through which streams of air under ressure are delivered into the lower art 0 the solution, a sweep operating adacent the upper face 'of said body for the purpose of maintaining the heavier constitucuts of the solution in suspension and thereby preventing the' blanketing-of the air outlets of said porousbody.

3. In apparatus of the character described, the combination with a solutioncontaining tank, a porous body therein and spaced therefrom to form a chamber between itself and the bottom of the tank, andmeans for admitting an expansible fluid into said chamber, said porous body adapted the air outlets of said.

K having i to sub-dividethe fluid and deliver the same in numerous fine streams into the solution contained in the tank, of means operating in roximity to the upper face of the porous body adapted to maintain the heavier'constituents of the solution in a state of suspension to prevent the blanketing of the air outlets of said body.

4. In apparatus of, the character described, the combination with a solutioncontaining tank, a porous body therein and spaced therefrom to form a chamber between itself and the bottom of the tank, and mean for admitting an expansible fluid into said chamber, said porous body adapted to sub-divide the fluid and deliver the same in numerous fine streams into the solution contained in the tank, of a vertical shaft mount ed within said tank, and sweep-arms on the shaft operatin adjacent the upper surface of the porous ody and adapted to prevent the blanketingi of the air outlets thereof by maintaining t a heavier constitutents of the solution in a. state of suspension.

5. In apparatus of the character described, the combination with a solutioncontaining tank, a porous body therein and spaced therefrom to form a chamber between itself and the bottom of the tank, and means for admitting an expansible fluid into lll said chamber, said porous body ndnptulto jcctin substantially radially within the 19 subdivide the fluid and deliver the same in tank I ve said last-named meana.

numerous fine streams into the solution cnn- In testimon whereof I iii: my signntum mined in tho glnk, of nzcnna gpiimling in in presence 0 two witnesses. 5 nnximit to t e u or ace 0 he rous imdy nd ptcd to maintain the lmavii' con- JOHN CALMW' stiments of the solution in a state of auspen- Witnesaas:

Hion to Yrevent tim blankcting of the air 0. Wnxocx,

outlets 0 said body, and vertical bullies pro- H. T. Kmam'.

04mm 0! ma pun! any h mum to: I" an; ml. )7 tuna! m flcmmluiemr of Emma. wllhlikfl, D. 0. 

